Purpose-built centre for large salmon research

The preparations are almost over and research is officially about to begin at the new $6.5 million Experimental Aquaculture Facility (EAF) at Taroona in Tasmania.

Research leaders for the new facility are Chris Carter and Polly Hilder. Chris Carter is head of the Fisheries and Aquaculture Centre at the Institute for Marine and Antarctic Studies, where the EAF is based as part of the University of Tasmania.

Polly Hilder is manager at the EAF and together they will oversee the commercially focused research program, which aims to improve the health, nutrition and growth of Atlantic Salmon (Salmo salar).

The facility itself was funded by the Australian and Tasmanian governments, the Australian Seafood Cooperative Research Centre, the University of Tasmania and industry partners.

Equal industry partners are Atlantic Salmon producer Huon Aquaculture group and Skretting Australia, a division of the international agri-feed producer Skretting.

Chris Carter says the facility has been designed specifically for research on large Atlantic Salmon (more than one kilogram) and is the first of its kind in the Southern Hemisphere: a land-based seawater system using recirculation aquaculture technology.

“There has been a lot of research on much smaller fish and the results have been extrapolated to predict what would happen in large salmon. But many physiological and nutritional processes change as fish get larger, and these changes may be challenging to predict,” he says.

The design of the EAF will help researchers to isolate the effects of environmental factors from normal changes in the fish as it grows. There are 24 fibre-reinforced plastic research tanks, each capable of holding up to 40 fish.

Seawater for the facility is pumped from the nearby River Derwent and undergoes filtration to one micron and ultraviolet filtration before being stored for use.

The manager at the new facility, Polly Hilder, feeds Atlantic Salmon in the tanks. An automated surveillance system will trigger an alarm on her phone if anything at the facility needs urgent attention. Photo: Mary Brewer

Environmental conditions including light, water quality and temperature can all be controlled to examine climate change effects relevant to local conditions.

An important part of these controls is the new low-pressure oxygenation system customised for the site and supplied by BOC and Linde AG Engineers.

The purpose-built system involves a combination SOLVOX OxyStream and SOLVOX A and SOLVOX Stream to cater for diverse experimental requirements.

Twelve indoor tanks will be dedicated to biosecurity research, particularly the control of amoebic gill disease, Tasmania’s most costly finfish disease. Current treatment requires salmon to be bathed in fresh water up to six times.

In the 12 outdoor tanks, the dedicated recirculation system is capable of providing water at two different temperatures. While the ideal temperature for Atlantic Salmon is 15°C, they can tolerate temperatures from 5°C up to 20°C.

The experiments aim to see what variables can be altered to allow the fish to grow best when temperature stressors are added.

“In that way we can determine how different factors influence optimal growing conditions and transfer these learnings in a way that is appropriate in a cage environment,” Chris Carter says.

Experiments in the 12 seven-kilolitre, fibre-reinforced plastic research tanks will be conducted on fish that have been held on-site and grown for six months from approximately 100-gram smolt to large fish prior to the experimental period.

Experiments conducted in the seven-kilolitre tanks and the inside tanks will have a six-month experimental period.

The tanks have been modelled on those used at Skretting’s research station at Lerang, Norway, which will allow the facilities to be benchmarked against each other.

The managing director of Skretting Australia, James Rose, says the EAF brings new research prospects to Tasmanian aquaculture.

“Skretting Australia’s focus will be on the challenges unique to the Tasmanian Atlantic Salmon industry.

This includes developing functional feeds to support fish during high-temperature conditions as well as other key research areas,” he says.

Frances Bender, Huon Aquaculture co-founder and executive director, says this extension of aquaculture research in Tasmania will make an invaluable contribution to innovation, growth and sustainability of aquaculture in Tasmania.